Fetal aortic stenosis (AS) imposes pressure load on the developing left ventricle (LV) and leads to derangements in myocardial structure and function via mechanisms that are not well characterized.

Methods

We compared amniotic fluid NT‐BNP and troponin levels in fetuses with AS prior to fetal valvuloplasty and controls. We estimated correlations between NT‐BNP and fetal echo parameters and identify NT‐BNP cutoff associated with biventricular outcome

Results

Median NT‐BNP level was higher in fetal AS than controls (3858 vs 1737 pg/ml, p<0.012). In contrast, troponin levels were lower in fetal AS, with troponin > detectable in 0/25 (0%) AS cases compared to 22/85 (26%) controls (p=0.03). Of 25 fetal AS cases, 12 (48%) had biventricular outcome. Fetuses with NT‐BNP < 910 pg/ml were more likely to have biventricular (OR =10) compared to those ≥910 pg/ml (p=0.045). Higher NT‐BNP correlated with earlier gestational age and measures of larger left heart size.

Conclusion

NT‐BNP is elevated in fetal AS, suggesting that LV pressure load and increased wall stress lead to maladaptive stretch‐related myocardial remodeling. Troponin is normal in mid‐gestation fetal AS, suggesting that ischemia is not the primary factor in fetal response to LV pressure load.

Abstract
The single radial immunodiffusion assay has been the accepted method for determining the potency of inactivated influenza vaccines since 1978. The world‐wide adoption of this assay for vaccine standardisation was facilitated through collaborative studies that demonstrated a high ... mehr

Abstract
Background
Whether morbidity from the 1918‐19 influenza pandemic discriminated by socioeconomic status has remained a subject of debate for 100 years. In lack of data to study this issue recent literature have hypothesized that morbidity was “socially neutral”.
Objectives ... mehr